There have been essentially two approaches in the prior art to the design of resin encapsulated A.C. industrial solenoids. One is typified by U.S. Pat. No. 3,605,054 and the other by U.S. Pat. No. 3,633,139. In the former, the coil and laminated frame are encapsulated in a resin block, the plunger is inserted and a hollow cap is then secured to the block over the plunger head, sufficient space being provided within the cap to allow reciprocation of the plunger head. The block is then secured to the device to be actuated. In the latter patent, the plunger is contained in an armature tube closed at one end and secured at the other to the device to be operated. The coil and laminated frame are encapsulated in a resin block having an aperture extending therethrough and the block is telescoped over the tube and secured thereto. In both instances essentially all that is resin encapsulated is the coil and field frame and other parts must be added to complete the housing for the plunger.